This could be the moment that Saudi Arabia finally loses Washington. Over the weekend, Turkish officials told my colleagues that veteran Saudi journalist Jamal Khashoggi, who vanished after entering the Saudi consulate in Istanbul last week, was murdered by a 15-member Saudi team dispatched to kill him. According to a U.S. official briefed by Turkish counterparts, Khashoggi’s body was likely dismembered, removed in boxes and flown out of the country.

The grisly claims sent a jolt through the U.S. capital, which is traditionally friendly territory for Riyadh. Khashoggi, 59, had recently moved to the United States in self-imposed exile. He wrote columns for The Washington Post’s opinions section and counted many American intellectuals and journalists among his friends.

If his killing is confirmed, it could prompt a decisive change in how the United States deals with Saudi Arabia. Leading Republican and Democratic lawmakers issued notes of alarm over the reports of Khashoggi’s death and threatened repercussions if they are true.

I pray Saudi journalist Jamal Khashoggi is alive. But if this deeply disturbing news report is confirmed, the United States & the civilized world must respond strongly, and I will review all options in Senate. https://t.co/LzrKiRveRp

Saudi authorities have vehemently denied the claims as “baseless allegations” and said a team of Saudi investigators had arrived in Istanbul to assist the Turkish inquiry into Khashoggi’s disappearance. Saudi officials in Istanbul took a team of journalists inside the consulate in a bid to prove their innocence. Meanwhile, reports in Saudi media attempted to discredit the accounts of Khashoggi’s fiancee, who first reported that he was missing on Tuesday.

No Turkish official has yet publicly confirmed that Khashoggi is dead. In remarks made Sunday, President Recep Tayyip Erdogan said only that the mystery was “very, very upsetting” and he was “chasing” the matter.

But many Turkish officials seemed confident in the assessment that the Saudis carried out murder. “There is concrete information; it will not remain an unsolved case,” said Yasin Aktay, an adviser to Erdogan’s Justice and Development Party, in a Sunday interview with CNN Turk.

At the time of writing, the Trump administration had not responded to the allegations. Secretary of State Mike Pompeo, as well as State Department spokeswoman Heather Nauert, spent the weekend on a mission to the Korean Peninsula. President Trump issued no tweets on Khashoggi. That’s not surprising: While Trump and his lieutenants routinely point to the “malign” actions of Iran in the Middle East, they have both enabled and ignored abuses carried out by the Saudis.

Since becoming the heir to the throne last year, Crown Prince Mohammed bin Salman, or MBS, has touted his reform plans, promising to liberalize his country and earning plaudits from a host of American commentators. But MBS’s de facto reign has also seen him terrorize rivals and arrest numerous feminists and civil-society activists, including some who now face the death penalty. Analysts argue it’s part of MBS’s need to further consolidate power.

“He wanted everyone to understand that women were being allowed to drive not because they had campaigned for it, but because their rulers had issued a decree,” wrote Lindsey Hilsum, the international editor of Britain’s Channel 4 News. “The point was clear: Civil disobedience will not bring results; changes will come only from submission to a benign monarch who will decide what is best.”

Trump is not bothered by monarchical excesses in Riyadh. On a visit there in 2017, Trump celebrated the Saudis as stalwart friends who would partner with the White House in its bid to confront Iran. He has also repeatedly hailed the Saudis' willingness to lavish tens of billions of dollars on American military hardware.

But in Congress, there is growing disquiet over the apparent carte blanche the White House has given the Saudis, particularly as the United States continues to back the bloody Saudi-led intervention in Yemen, which has seen mounting civilian casualties.

“Lawmakers on both sides of the aisle, long suspicious of Saudi religious extremism and historic ties to terrorism, more recently have been highly critical of Saudi actions in Yemen and at home,” wrote my colleague Karen DeYoung. “Only last month, they were dissuaded by the administration from stopping U.S. military sales and assistance to the kingdom — the world’s largest purchaser of American defense hardware and a key partner in White House plans to bring Iran to heel and to forge an Israeli-Arab alliance.”

If Khashoggi’s alleged murder is confirmed, that political scrutiny will only deepen. And while the American public may not be bothered by the disappearance of an outspoken Saudi journalist, Khashoggi’s case is likely to shadow all discussions of U.S.-Saudi ties in Washington. American commentators who conducted lengthy interviews with the crown prince as part of Riyadh’s PR push earlier this year have already sounded off, demanding action.

President Trump must ask Saudis to give full and credible account of what happened to Jamal Khashoggi inside their Istanbul consulate. And tell us what he knows too.

If my friend Jamal Khashoggi’s death is confirmed, it is a monstrous outrage. Those responsible will pay a severe price. We loved Jamal’s honesty; we won’t forgive those who tried to silence him. https://t.co/N0HzB6xkTA

The brazenness of Khashoggi’s apparent assassination sends a chilling message to other Arab dissidents in the Middle East. Though Turkey has its own atrocious record of detaining journalists, Istanbul has become a sanctuary for exiled opponents of regimes across the region. The disappearance of Khashoggi — who, in his columns for The Post, was a thoughtful, constructive critic of the Saudi leadership — suggests that other critics may not be as comfortable as they think.

That seems to be the goal of MBS and his father, King Salman. “Their foreign policy is based on a single doctrine: establishing the supremacy of Saudi Arabia in order to make it the sole arbiter of Arab affairs and the main point of entry for all international powers into the region,” wrote Madawi al-Rasheed, a Britain-based academic and critic of the Saudi government, in a new collection of essays on the kingdom.

“Every single Saudi I know is terrified reading this, openly or secretly,” tweeted Sarah Leah Whitson of Human Rights Watch. “It really means the Saudi government can kill any of them, anywhere. No escape. And that’s exactly what MBS what’s them to think.”